U.S. patent application Ser. No. 07/427,135, filed Oct. 16, 1989 and allowed Aug. 20, 1991, discloses apparatus in which a film sheet is unloaded from a cassette by suction means and fed to a driven pair of transport rollers. An optoelectronic interrupter switch arranged in the transport path of the sheet and upstream of the transport rollers senses a sheet film. This activates control means which terminates the vacuum from the suction means so that the sheet when fed into the nip of the rollers is no longer held by the vacuum means. Such a switch requires considerable space for installation of the oppositely arranged transmitter and receiver components, each of which must have electrical connections.